Furnace.



C. A. CADWELL.

FURNACE.

APPLICATION FILED JAN. 26, 19M.

1 200,466 Patented Oct. 10, 1916.

2 SHEETSSHEET L irrola/v/fgg c. A. CADWELL.

FURNACE.

APPLICATION FILED MN. 26. 1914.

1 ,'200,466. Patented 001;. 10,1916.

2 SHEETS-SHEEI 2.

,ez ummli i gy 4 fg? g 13 We -5 m: Name's PETERS ca. PNOm-LITHO wAsmncrau. n. cy

unrrnn STATES PATENT OFFICE.

CHARLES A. GAEWELL, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC RAILWAY IMPROVEMENT OOMIANY,OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

FURNACE.

To all whom it may concern:

Be it known that I, CHARLES A. CAD- WELL, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Furnaces, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The present improvements, relating as'indicated, to furnaces, have more particular regard to the construction of a melting furnace, such as a furnace for heating crucibles and the like, although the several features of improvement involved are not necessarily limited to use in this connection.

The object of the invention is to provide a furnace of the character in question, that will be light, compact and readily trans-- ported and in general adapted for use out of doors, that is, in the field. A' particular field of use for a furnace of this sort is found in practising the process of forming electric rail bonds directly in place on the rails, which forms the subject matter of U. S. Patent No. 750,510 to W. H. Wherry. In practising such process, molten metal is poured upon the rail-bond terminal and juxtaposed rail face until they are sufficiently heated and softened to allow of the intimate and permanent union of the metal and rail; and it hence becomes necessary to provide an adequate melting furnace for supplying, close at hand to the work, the necessary molten metal, which usually is copper.

To the accomplishment of the foregoing" and related ends, the invention then consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and thefollowing description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings: Figure 1 is a side elevation of my improved furnace, with its appurtenant parts, as arranged for use in a connection such as that referred to above; Fig. 2 is a plan view of the same;

j Fig. 3 is a plan view of the furnace proper Specification of Letters Patent.

Patented Oct. 10, 1916.

Application filed January 26, 1914. Serial No. 814,336.

with cover removed to more clearly show the lnterlor construction; Fig. 4 1s a vertical longitudinal section of said furnace; and

Fig. 5 is a section of a portion of the furnace by transverse members 4, under which are mounted rollers or wheels 5, two at the one end, and one at the other, so that the frame and parts supported thereby can be rolled along the rails 3.

The furnace 6 proper, of general cylindrical'form, rises vertically above the frame, being located substantially midway between its ends and is firmly secured in place by means of side braces 7 of the form clearly appearing in Figs. 1 and 2. On one end of the frame and adjacent to the furnace is a tank 8 arranged to contain the fuel, which will ordinarily be oil, either kerosene or fuel oil, so called, such tank being providedwith a pump 9 by means of which a predetermined pressure may be maintained upon its contents, as indicated by a gage 10. A valve-controlled connection 11 is also provided, leading to a heating coil in the furnace, as will be presently described. Supported on the'frame next adjacent to the tank is a supply andtool box 12.

As indicated above, the furnace proper is of general cylindrical form having an inner and outer shell between which is interposed heat-insulating material 13,the inner shell being furthermore lined with fire clay 14. Projecting from the side of the furnaceopposite to the oil tank is a hollow extension 15 of oblique conical shape in longitudinal cross section, the passage 16 therein gradually increasing in diameter from the outer end of the extension to the furnace chamber, into which it opens. A series of transverse slits 17 are formed in the under side of such extension whereby air may be admitted, as will be explained more fully in describing the operation of the furnace.

Embedded in the upper portion of the clay lining 14 of the furnace chamber proper is a coil 18 to which the oil supply line 11 from tank 6 is connected, such connection being with the lowermost end of the coil, the latter comprising a plurality of turns one above the other and the uppermost turn lying flush with the upper surface of the lining in question so as to be in effect exposed. Preferably such upper turn is double, one turn lying within the other as shown, the line thence extending into a metalbox or stove 19 on the upper face of the extension 15 and making a plurality of turns within such box. From the latter, the line projects as shown and terminates in a recurved portion 20 directly in front of the outer end of the opening-16 in such extension, being provided with a pin-hole nozzle 21, so that the fuel under pressure will be sprayed into the opening, where it may be ignited along with the air drawn through such end and through the series of slots 17.

Ordinarily the furnace chamber will be closed by means of a cover in the form of a circular plate 22 of fire clay, or like material, which has merely a central opening 23 to allow the escape of the gases of combustion. This cover is operable by means of a handle 24 attached thereto, in conjunction with a bracket 25 projecting in the same direction and arranged to slide upon a way provided by two parallel extending bars 26. The position of the handle and bracket relative to each other is such that by pressing down on the outer end of the handle the cover may be tilted so as to clear the upper furnace walls, and thereupon such cover may be slid along the ways until the furnace is entirely uncovered, thus permit ting access to its interior for the purpose of inserting or removing the crucible 27 or other object to be heated.

To start the furnace in operation a fire of wood, charcoal or other suitable combustible material is kindled in the stove box 19 through .which the coil last passes. Upon opening the valve in line 11, the oil will be forced through the coils of the line by the pressure in the tank 8 and will be sufficiently heated by the fire kindled in the stove to readily gasify and ignite as it is sprayed into the furnace through the 'extension 15. The combustion is rendered complete by the admissionof air through the series of air inlet slots 17 in the bottom of the extension, so that as the blast passes along the latter, an increasing amount of oxygen is rendered available for the combustion. Initially, during this preliminary heating stage, the cover, although over the gases of combustion will escape, not merely by the central opening in the cover, but also through the annular space left between the latter and such furnace chamber. The heated gas and flame thus escaping, pass directly over the last turns of the coil 18 embedded in the clay lining 15 of the chamber, so that these coils are quickly brought to a high temperature and thus the supply of fuel is almost immediately brought to the desired temperature. As soon as this result is attained, the cover is lowered again into the position shown in Figs. 1 and 4;, thus, preventing the excessive heating of the more exposed turns of the coil just re ferred to. The lining in the meantime becomes sufliciently heated to heat the other turns of the coil and the further operation is continuous, it being understood that the fire in the box 19 is used only at the very beginning, the turns of the coil in such box being subsequently maintained at the proper temperature by the heat radiating from the upper wall of the furnace extension.

With the foregoing apparatus, it has been found possible to produce in the field or anywhere, a very high temperature in an extremely short time, the furnace operating With a maximum of efficiency under all conditions of use. At the same time the apparatus is light, as well as simple in construction, so that it can be readily manipulated by even two operators. In fact, a single operator can use the apparatus once it is in place on the rails, as it can be rolled along the rails with little effort. Particular attention is called to the arrangement for heating the fuel before it is injected into the furnace, as also to the construction of the extension in which the oil thus sprayed is first received. If desired means may be provided for regulating the size of the slits 17 in extension 15, such means be ing shown in Fig. 6 as taking the form of a shutter 29, the mode of operation of which should be evident.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In a furnace, the combination with the furnace chamber proper, of a lateral exten sion having a passage communicating with said chamber, said extension having a series of transverse slits on its under side opening into such passage, means adapted to adjust the size of such slits, and a nozzle arranged to inject fuel through such passage into said chamber.

2. In a furnace, the combination of the furnace chamber proper, a movable cover therefor, a nozzle arranged to inject fuel into said chamber, and a fuel supply line connected with said nozzle, said line including a preheating coil and the position of said cover being adapted to regulate the temperature of such coil.

3. In a furnace, the combination with the furnace chamber proper, of a nozzle' ar ranged to inject fuel into said chamber, and a fuel supply line connected with said nozzle, said line including a coil embedded in the wall of said chamber and normally protected from the gases of combustion, but adapted to be directly exposed to such gases when desired.

4. In a furnace, the combination with the furnace chamber proper, of a nozzle arranged to inject fuel into said chamber, a fuel supply line connected with said nozzle, said line including a coil embedded in the wall of said chamber and having a part lying flush with the surface of such wall, and a cover normally protecting such coil part but adapted to be raised to expose the same directly to the gases of combustion.

5. In a furnace, the combination with the furnace chamber proper, of a lateral extension having a passage communicating with said chamber, a nozzle arranged to inject fuel through such passage into said chamber, and a fuel supply line connected with said nozzle, said line including a coil disposed above said extension, so as to be heated thereby.

6. In a furnace, the combination With the furnace chamber proper, of a lateral extension having a passage communicating with said chamber, a nozzle arranged to inject fuel through such passage into said chamber, a fuel supply line connected with said nozzle, said line including a coil disposed above said extension, so as to be heated thereby when the furnace is in operation, and means adapted to preliminarily heat such coil.

7. In a furnace, the combination with the furnace chamber proper, of a lateral extension having a passage communicating with said chamber, a nozzle arranged to inject fuel through such passage into said chamber, a fuel supply line connected with said nozzle, said line including a coil disposed above said extension, so as to be heated thereby when the furnace is in operation, and a box inclosing such coil and adapted to have a fire kindled therein to preliminarily heat said coil. 7

8. In a furnace, the combination with the furnace chamber proper, of a lateral extension having a passage communicating with said chamber, a nozzle arranged to inject fuel through such passage into said chamber, and a fuel supply line connected with said nozzle, said line including a coil embedded in the wall of said chamber and another coil disposed above said extension.

9. In a furnace, the combination with the furnace chamber proper, of a lateral extension having a passage communicating with said chamber, a nozzle arranged to inject fuel through such passage into said chamber; a fuel supply line connected with said nozzle, said line including a coil embedded in the wall of said chamber and adapted to be directly exposed to the gases of combustion when desired, and another coil disposed above said extension, so as to be heated thereby when said furnace is in operation, and means adapted to preliminarily heat such second coil.

Signed by me, this 22d day of January, 1914.

CHARLES ACADWELL.

Attested by- D. T. DAvms, JNo. F. OBERLIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, I). 0. s 

